In doing so, he or she ensures that the students will be drilled in the intended principles and concepts. In addition, the instructor may provide appropriate hints for some of the more difficult problems. With regard to symbols, in the text material I elected to boldface those symbols that are italicized in the textbook. Furthermore, I also endeavored to be consistent relative to symbol style.

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Members Adhemar C. Oliveira Jr. Canevarolo Jr. Pinto Paula Moldenaers Richard G. Editorial Section News E3 Agenda E4 Funding Institutions Cover: Typical disc surface roughness measurements for three test repetitions; a turning. Arts by Editora Cubo. These market launches and product improvements are important technology advancements and thus accelerate the transformation to a circular economy of plastics. Borealis and its wholly-owned subsidiary, mtm plastics, will showcase the new Borcycle technology and recyclate innovations at the K in October.

By capitalising on its profound expertise in virgin polyolefins and collaborating with value chain partners, Borealis keeps discovering new opportunities for business growth within the circular economy. As a transformative technology, it complements the existing Borealis virgin polyolefins portfolio with a range of pioneering, circular solutions.

As a scalable and modular technology, Borcycle has been developed to meet growing market demand for high-quality recyclate. Leading appliance brand owners, for one, have pledged to increase the amount of recycled plastics in their goods.

Yet until recently, producers have not been able to rely on a consistent supply of high-quality recyclate. The Borcycle technology will help address this challenge. Compounds made using the Borcycle technology deliver high performance, add value and offer versatility. Producers and brand owners in a range of industries will profit from the availability of high-quality recyclate that helps them meet environmental and regulatory challenges. The launch of our new recycling technology Borcycle is tangible proof of our commitment to achieving plastics circularity.

A number of significant improvements have been made to existing recyclate grades in the Purpolen portfolio. Recycling, Borealis Circular Economy Solutions.

Bottlebrush Polymers: A Green Strategy for Purifying Natural Gas Natural gas and biogas have become increasingly popular sources of energy in recent years thanks to a cleaner and more efficient combustion process compared to coal and oil. However, the presence of contaminants, such as carbon dioxide, means it must first be purified before it can be burned as fuel. Unfortunately, traditional processes used to purify natural gas typically involve the use of toxic solvents and are extremely energy-intensive.

Now, researchers at the Massachusetts Institute of Technology MIT describe a new type of polymer membrane that can dramatically improve the efficiency of natural gas purification while reducing its environmental impact.

The membrane is capable of processing natural gas much more quickly than conventional materials, according to graduate student Yuan He. Instead of using long chains of polymers, Smith and his team have designed membranes in which the strands look like hairbrushes, with tiny bristles on each strand that allow the polymers to separate gases much more effectively.

The membrane is also 2, -7, times more permeable than traditional membranes. The researchers are now planning to carry out a systematic study of the chemistry and structure of the brushes in order to investigate how this affects their performance.

Source: Advanced Science News - www. Collective Members Master Polymers Ltda. Nexo International Ltda. Radici Plastics Ltda. Uniflon - Fluoromasters Polimeros Ind. Abstract Heat-moisture treatment is type of physical modification that which cause changes in the technological characteristics of the starch.

Starch extracted from sweet potato resulted in a product of high purity. All modified starches showed a higher water absorption capacity when compared to native starch. The morphology of the starch granules remained unchanged after the modification and the same was observed with respect to the crystallinity.

Keywords: physical modification, tubercle, quality. How to cite: Cavalcanti, M. Introduction The sweet potato Ipomoea batatas belongs to the Convolvulacea family and is an easily-adaptable rustic tuberous vegetable tolerant to dry seasons. It is a relatively low cost production crop of great economic and social importance in developing countries[1]. The process of extracting this carbohydrate is of great interest to the food, pharmaceutical and chemical industry, because it presents physicochemical characteristics as, solubility, swelling power, pasting property, thermal, among others[2].

In its native form, starch often does not possess appropriate physicochemical properties for some types of processing. In this sense, the modifications of starches from alternative sources provide the amplification of use and favor the commercialization of starch.

Among the types of modifications, the physical modification by heat-moisture treatment has been highlighted with the advantage that the obtained starch is considered a natural and highly safe material[3]. Materials and Methods 2. Cavalcanti, M. The determination of particle size was performed based on micrographs with a magnification of x using ImageJ software. The crystallographic phases of the samples and the standard JCPDS plots representing them were determined by the X-ray diffraction curves.

Results and Discussion 3. The starch presented good quality and efficacy in the implemented extraction process, with carbohydrate content sugars plus fibers of about As described in the literature, sweet potato starch is considered to have high amylose content and to have influence on starch properties[10].

When comparing the apparent amylose content in the native starch Similar behavior was observed regarding oil absorption capacity OAC , where the modified starches presented higher values of starch, being 1.

Starch with low water absorption capacity is indicated as an ingredient in products that require both low retention of water and fat, improving characteristics such as product crunchiness. However, all starch types presented ellipsoidal and rounded granules, with noticeable agglutination tendency in starches modified by heat-moisture treatment.

A small increase in particle size by 6. Average particle size may be related to the amylose content, considering that the HMT 20 treatment had the highest amylose content. Because starch granules are partially crystalline, they are defined based on the interplanar spaces and the relative intensity of the X-ray diffraction lines. According to these authors, type A starch is a typical cereal starch, Type B is associated with tuberoses or amylose rich materials, and Type C starch resembles pea starch and various bean starches.

Type V starch is a type of crystalline starch typical of complexes formed between amylose and lipid. The amylose content found in the starches corroborates with the crystallinity results, once, ranged from Figure 1.

Conclusions The extraction of sweet potato starch results in a product of high purity and good quality. The heat—moisture treatment caused morphological changes and water absorption capacity. Figure 2. Based on the crystallinity values of the modified starches, the increase of the crystallite in relation to the original starch 7. However, the HMT 15 stood out from the others, obtaining 8. References 1. Nunes, M. Horticultura Brasileira, 30 2 , SS Zhu, F.

Physicochemical properties of sweetpotato starch. Starch, 63 5 , Bemiller, J. Starch modification: challenges and prospects. Starch, 49 4 , Huang, T. Food Hydrocolloids, 54 Part A , Adebowale, K. Effect of heat—moisture treatment and annealing on physicochemical properties of red sorghum starch. African Journal of Biotechnology, 4 9 , Approved methods 8th ed.

Martinez, C. Guia de estudo para ser usada como complemento de launidadauditutorial sobre elmismo tema 3. Cali: CIAT. Hormdok, R. Hydrothermal treatments of rice starch for improvement of rice noodle quality. Lebensmittel Wissenchaft und Tecnologie, 40 10 , Beuchat, L. Functional and electrophoretic characteristic of succinylated peanut flour proteins. Journal Agriculture Chemistry, 25 2 , Feng, W. Analysis of phosphorylation sites.

Kaur, M. Influence of heat-moisture treatment HMT on physicochemical and functional properties of starches from different Indian oat Avena sativa L. International Journal of Biological Macromolecules, ,


respostas callister 5 ed.






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